(19)
(11) EP 1 691 483 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
08.11.2006 Bulletin 2006/45

(43) Date of publication A2:
16.08.2006 Bulletin 2006/33

(21) Application number: 06002742.2

(22) Date of filing: 10.02.2006
(51) International Patent Classification (IPC): 
H03K 19/018(2006.01)
B60L 11/18(2006.01)
H02M 7/48(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR
Designated Extension States:
AL BA HR MK YU

(30) Priority: 10.02.2005 JP 2005034848

(71) Applicant: HITACHI, LTD.
Chiyoda-ku Tokyo 100-8280 (JP)

(72) Inventors:
  • Inaba, Masamitsu
    Tokyo 100-8220 (JP)
  • Iwamura, Masahiro
    Tokyo 100-8220 (JP)
  • Shigeta, Satoru
    Tokyo 100-8220 (JP)

(74) Representative: Beetz & Partner 
Patentanwälte, Steinsdorfstrasse 10
80538 München
80538 München (DE)

   


(54) Interface circuit, power conversion device, and vehicle-mounted electric machinery system


(57) The invention relates to an interface circuit (4) capable of reliably transmitting signal even when there is fluctuation in the potential difference in reference potentials between circuits between which signal transmission is carried out. An interface circuit (4) is comprised of a level shift circuit (20) and a potential selection circuit (10) for selecting the potential of a power supply voltage for operating the level shift circuit (20). The potential selection circuit (10) selects one of a plurality of input potentials. The level shift circuit (20) receives a voltage pulse having a first potential as reference potential and outputs a voltage pulse having a second potential as reference potential. The level shift circuit (20) is operated on the basis of both a potential difference between the output potential from the potential selection circuit and the first potential and a potential difference between the selected potential and the second potential.







Search report